Cleaning the PDMS window of Ember's resin tray


In order to print successfully with Ember, the PDMS window of the resin tray must be clean and optically clear. The dirtier the PDMS is, the greater the likelihood becomes of print failure.

Here's how to clean the PDMS:

Materials required:

  1. Nitrile gloves
  2. Safety glasses
  3. A light-proof container in which to store resin
  4. Acetone (nail polish remover)
  5. Lens paper
  6. Paint strainer (if the resin needs to be filtered clean of cured parts)


  1. Put on nitrile gloves and safety glasses.
  2. Pour the resin out of the resin tray into a light-proof container. [If your previous print failed, pour the resin through a paint strainer, to remove any bits of cured resin.]
  3. Soak lens paper with acetone. Do not use isopropanol / isopropyl alcohol, as it won't work. Do not use paper towels, dirty rags, or anything abrasive, as this will scratch and damage the PDMS.
  4. Wipe the window with an acetone-soaked lens paper. Avoid touching the edge of the window frame, as the acetone will dissolve some material out of the frame.
  5. Breathe onto the window so that it fogs up. Wipe the window with a clean piece of lens cloth.
  6. Repeat until the window is clean and does not have spots or streaks.

If you have any questions about the process, post them in the comments.


Do you think the B9 creator PDMS would work in the ember?

They have a refill procedure which involves mixing two compounds and letting them set over about 48 hours, and I wondered if this might work in an otherwise dead tray once the PDMS had clouded up too much.

The B9 tray is designed with re-use in mind, but I've seen instructables indicating the Ember PDMS might be replacable the same way... and I'd be curious if anybody else had tried it.


Hey Barry,

We wrote an instructable about how to create your own PDMS window!

A couple of things to be aware of if you make your own windows:

  1. Ember's PDMS windows are made using a precision injection molding process, which gives them a surface planarity tolerance of +-50microns. Its important that the surface of the window is very flat so that the resin tray doesn't jam during the rotation separation
  2. Make sure you seal the window very well into the resin tray and test it for water-tightness before using it

Lets us know how you get on!



The user manual section found here somewhat contradicts what is mentioned in the post, as we are told to use IPA to clean the PDMS window. Which one is the right procedure?


For Old version of tray, IPA will ruin the seal. For New Tray, I use IPA and then liquid dish soap to clean out the tray (less than 5 minutes for IPA). I don’t really have any problem.


So you use acetone and lens wipes to clean the window what about the residual UV material that is left in the tray?


If your careful - yes. Wet a cloth and wipe - do not flood the PDMS (let it get on anything else).